Method and apparatus for precision turning

Abstract

Method and apparatus for precision turning horizontally clamped workpieces which are inclined to sag, by means of a numerically controlled lathe.

What is claimed: 
     
       1. Apparatus for precision turning horizontally clamped workpieces which are inclined to sag comprising: (A) a numerically controlled lathe having a cross-slide;   (B) a sleeve mounted axially displaceably for limited movement in a bore in said cross-slide and extending in the tool feed direction of the lathe, said sleeve being normally biased outwardly;   (C) said sleeve having a pair of outwardly extending diverging arms at the proximal end thereof;   (D) a first measurement pickup disposed within the sleeve near the distal end thereof for determining the displacement of the sleeve;   (E) a plunger axially displaceably disposed for limited movement in said sleeve at the proximal end thereof and extending outwardly between said arms, said plunger being normally biased outwardly; and   (F) a second measurement pickup disposed in the sleeve near the proximal end thereof for determining the displacement of the plunger;   (G) whereby when said arms are placed over a workpiece, said plunger is displaced in relation to said sleeve until said arms abut the workpiece, thereby measuring the workpiece diameter through said second pickup, and said sleeve is then displaced in relation to said cross-slide, thereby measuring the slack of the workpiece through said first pickup.   
     
     
       2. Apparatus according to claim 1, wherein said sleeve has a collar at the distal end thereof and is biased outwardly by a spring disposed between the collar and the distal end of the bore, said bore having a shoulder against which said collar rests. 
     
     
       3. Apparatus according to claim 1, wherein said plunger has a collar bearing against a shoulder at the proximal end of said sleeve and is biased outwardly by a spring bearing against said collar.